140
c
HAPTER
8:
Service
Model 335 Temperature Controller
The components on this board are electrostatic discharge sensitive (ESDS) devices.
Follow ESD procedures in section 8.11 to avoid inducing an electrostatic discharge (ESD)
into the device.
1. Turn the Model 335 power switch Off. Unplug the power cord from the wall out-
let, then the instrument.
2. Stand the unit on its face. Use the hex driver to remove the four screws on both
sides of the top cover; set aside these screws. Loosen the two rear bottom screws
(FIGURE 8-9).
Cover and option plate screws
Remove
rear plastic
bezel
Remove
top side
cover screws
(both sides)
Loosen
bottom
rear side
cover screws
(both sides)
To remove top
cover, slide it
to the rear on
the tracks
Rear panel option plate screws
3. Remove the rear plastic bezel. The cover is tracked. Slide the top cover to the rear
on the track to remove it.
4. Remove the rear panel option plate screws; these screws are not used for the rest
of the installation. Remove the rear panel o
5. ption plate.
6. Lay the instrument on its feet, and turn it to view the inside circuit board.
7. Place the Model 3060 card into its position in the rear panel from inside the
instrument. Orient the card so that the circuit board overhang faces the bottom
of the instrument.
Align the 3060 card with input A and B
8. Locate the screws included in the 3060 option kit. Attach the card by starting
both of these screws in a few threads before tightening either(FIGURE 8-10) .
9. Fully tighten both screws.
FIGURE 8-9
FIGURE 8-10
